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UPDATE: TAKING ORDERS
I am now ready to accept orders. I want to make sure that people are clear about what is on offer (as some PMs I have received suggest I may have caused confusion). There are two options:

OPTION 1: PCB and chipset
You will receive a PCB and the two Yamaha ICs. You will have to source all the other components. You will then have to assemble the board. This (obviously) involves soldering.

Price for this is £7.00 including 1st class post within the UK. (Alternatively, you can pick it up from me at an event for £5.50.)

OPTION 2: Complete kit
You will receive a PCB, the two Yamaha ICs and all the other parts required for a standard build. You will still have to assemble the board. This too will involve soldering.

Price for this is £13.50 including 1st class post within the UK. (Alternatively, you can pick it up from me at an event for £12.00.)

Just to be clear, both options involve soldering.

In addition to the above you will need to source a 34-way female to female IDC cable and a 5V DC power supply with a 2.1mm barrel connector. (Pretty much anything will do as it only draws 30mA. I use a USB phone charger and an adapter cable.)

How to order
Please send me a PM with details of whether you want a complete kit or a PCB and chipset. Please also give me details of where you want it posted to. Please could payment be by PayPal 'friends and family'. I will reply with details of my PayPal registered email.

If you would rather collect this from an event, please still send me a PM with details of whether you want a complete kit or a PCB and chipset and which event you want to collect from (RISC OS London or ABUG Bolton). I am happy to take payment by PayPal now, but I am equally content to take cash at the event when you pick it up.

I hope this is all clear and OK with everyone.

Finally, I am still looking into a solution for anyone who is uncomfortable with soldering and, therefore, wants a ready made card. I hope to post details of this in the next few weeks.

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A small number of people have asked me whether they could have one of my BeebOPL boards and I thought it may well be worthwhile checking whether there is any wider interest.

I would make these available at cost. Depending on the extent of interest, I think one board together with the two Yamaha chips would cost about £6 or £7. All the other parts are readily available from the usual electronic component stockists. If there were sufficient interest, however, I could also buy the parts in one go (thereby avoiding additional P&P charges). If I did that, I suspect that a complete kit of parts (including the board and the two Yamaha chips), with sufficient numbers, would cost about £14 or £15. The only other things necessary would be 5V power and a 34 way IDC ribbon cable.

The card is based on the YM3812 which was the chip in the Ad Lib Sound Card and the first Soundblaster card.

I have put together a playlist on SoundCloud which demonstrates what the board is capable of. All the recordings are made directly from the audio output of the BeebOPL board.

Been waiting to get my hands on this since I first saw it demoed in Bolton, but I don't have any assembly skills. Would you consider offering fully assembled/populated boards? Either way I'd like two complete kits please; loose or if possible, fully assembled. Happy to pay whatever price you determine for complete boards!

Hope to see lots of other StarDotters picking up this magnificent piece of kit whilst they're available!! OPL2 is a thing of beauty!!

UPDATE
I have ordered a run of PCBs. They should be here in a couple of weeks.

I am now in a position to provide a more accurate estimate of costs. A PCB plus the two Yamaha chips is likely to cost about £6.10. The price for the complete kit is likely to be about £12.50. Both these prices include UK shipping by first class post. (For those of you who are going to Bolton and are happy to wait until then, I can bring them up with me. This will reduce the cost by £1.27.)

The biggest uncertainty is whether or not I will incur charges when the PCBs pass through customs. I won’t know this until they arrive. If there are customs charges, my best estimate is that this will add about 60p to the above prices.

When the boards arrive and I am happy that they are OK, I will start taking payments. I trust everyone is happy doing this as a ‘friends and family’ PayPal payment. (People to whom I am 'hand delivering' can pay cash if they prefer.)

I am also working on a solution for people who want a fully assembled board. If this comes to fruition, the cost of this will be somewhat more than the prices quoted above. Also, this option will not be available immediately. People wanting assembled boards will have to wait a little longer.

Just in case there is anyone who hasn't put their name down who is interested, I will have a number of boards left over.

I have made a number of changes to the design since the original prototype. Thanks to a very helpful suggestion from 1024MAK, I am now using a 74HCT688N to do the address decoding. This has reduced the chip count and, consequently, the cost of parts.

I have also included a number of optional variations based on certain aspects of the design of the Mk2.3 version of the BeebSID board. These include the following:

Terminating resistor networks on the 1 MHz bus

Use of a power MOSFET as reverse-voltage input protection

Use of a voltage regulator as a kind of over voltage-input protection

Power LED

Alternative connectors for power and audio that would assist mounting the board in a case or inside a Beeb.

As explained above, all of these are entirely optional. None are needed to build a fully functional board and the necessary optional parts will not be included in the kits.

Finally, I am doing everything I can to keep the cost of the kits to an absolute minimum. To that end, I am looking at the possibility of supplying CMOS ‘HCT’ chips instead of the two TTL ‘LS’ logic chips; which may prove a little cheaper. HCT chips are meant to be voltage compatible with LS devices. HCT chips are working fine in my prototype board. But I want to check them out more thoroughly before making a final decision. If anyone has any concerns about this, please say so.

For the same reason (albeit a bit more straightforward), the kits will include the cheaper stamped pin IC sockets (and not the more expensive turned pin variety). Again, if this causes concern for anyone, please say so.

An updated schematic and other stuff is available on GitHub.

There is so much wonder in the universe; why should you want to imagine that there is more?

I should also add then I am going to be at the RISC OS London Show and, with a following wind across the South China Sea, I may well have the boards by then. So anyone who wants one and is coming to the Show can collect it them.

There is so much wonder in the universe; why should you want to imagine that there is more?

With regard to using CMOS HCT logic chips in place of LS types, here are my thoughts:

IC1 - using a 74HCT02 should be okay, I can see no problems with any part of the circuit.

IC3 - the only area that may cause problems with using a HCT type in place of a LS type may be the crystal oscillator section.

You already have a working prototype, so it's unlikely others will experience problems. If there are problems with a 74HCT04 in IC3 position, changing the values of the resistors should help. If you want to do some simple tests to be more certain and you can get hold of a 74HCT04 from more than one manufacturer, try each of them at different ambient temperatures, if they all work okay, that should be enough to prove the circuit will work for other users. Suggested method for different temperatures is simple. Just three should be fine: room temperature; 5oC meaning leave in the fridge for a couple of hours; and finally warm up the whole board in a warm place for a couple of hours (very warm airing cupboard or similar). Then test immediately

1024MAK wrote:With regard to using CMOS HCT logic chips in place of LS types, here are my thoughts:

IC1 - using a 74HCT02 should be okay, I can see no problems with any part of the circuit.

IC3 - the only area that may cause problems with using a HCT type in place of a LS type may be the crystal oscillator section.

You already have a working prototype, so it's unlikely others will experience problems. If there are problems with a 74HCT04 in IC3 position, changing the values of the resistors should help. If you want to do some simple tests to be more certain and you can get hold of a 74HCT04 from more than one manufacturer, try each of them at different ambient temperatures, if they all work okay, that should be enough to prove the circuit will work for other users. Suggested method for different temperatures is simple. Just three should be fine: room temperature; 5oC meaning leave in the fridge for a couple of hours; and finally warm up the whole board in a warm place for a couple of hours (very warm airing cupboard or similar). Then test immediately

Mark

Thanks.

I had though that the oscillator section might be a problem, but I had, in my naive way, just intended to see whether the clock traces on the 'scope were as 'clean' as with the LS04. I hadn't thought of different temperatures or different manufacturers so I will give that a try.
I am not sure I am going to make the costs savings I had hoped for (a particularly cheap chip seems to be out of stock). But I am keen to follow this through just for my own benefit and for future reference.

There is so much wonder in the universe; why should you want to imagine that there is more?

UPDATE
The PCBs have now cleared customs . Unfortunately there was a fairly hefty charge (effectively, 37% ) This means the prices have gone up a little.

My best estimate of cost now is as follows:

Full kit - £11.85 (plus £1.27 for 1st class postage)

PCB plus two Yamaha chips - £5.28 (plus £1.27 for 1st class postage)

Unless there is some big surprise, I don't expect those prices to change more than a few pennies. If you are coming to the RISC OS London Show at the end of the month or to ABUG Bolton next month, you can collect from me then and avoid the postage cost.

The PCBs will arrive in the next couple of days. I will have to build one to make sure everything is OK given the various design tweaks. I hope to then take firm orders and payment over the weekend and post out (to those who don't want to collect) some time next week.

There is so much wonder in the universe; why should you want to imagine that there is more?